The Ewelme Brook is fed from springs in the village.  The water having been filtered through the chalk is ideal for growing watercress due to its purity, its stable temperature and fairly stable flow regime.  Watercress occurs naturally and was no doubt harvested by the villagers for hundreds of years.  Serious commercial production began in the late 1800’s when George Smith bought two cottages and land beside the brook in 1886.  He and his brother Robert enlarged the beds and the watercress was not only marketed locally but was sent by train to London, Manchester and the Midlands.  The crop was harvested between February and June and a further crop could be taken in August and through the autumn. At its peak watercress was grown in Kings Pool and all the way down to Cottesmore.

Commercial production stopped in 1988.  The beds then became overgrown with weeds such as great willow herb. In 1991 Des Dix who lived beside the beds gained permission to clear the beds.  This was a massive undertaking and he was joined by work parties from the village and elsewhere.  In 1999 The Chiltern Society was able to buy the beds to secure their future.   The area is now a Local Nature Reserve and it is maintained by a management team sourced from villagers and other local interested people.  More information is available at the Watercress Centre and in two books, ‘Ewelme Watercress Beds’ and ‘Our Stream’. Guided tours take place on the first Sunday of each month.